I would say the oversized filter will be fine. You can simply run the pump for less time each day and enjoy longer periods between DE changes.
As for the liner, I am in the j-hook liner camp. I replaced my original liner this year. I talked with my LPS and they wanted $500 for the same liner I purchased originally and $350 for an overlap. I did some googling and I eBayed a $200 deal for my 21 foot pool. I received the liner and noticed it was for a beaded pool. I searched again and found that a beaded liner is different from a uni bead and different from a j-hook (what I had in my original liner).
This is short version of what I learned...
A beaded liner requires a bead receiver be installed on the top edge and the liner is then inserted into the bead area of the track. A j-hook liner has a section at the top of the liner that goes over the top edge of the pool anId is covered by track at the top of the wall. A uni-bead is both a j-hook and a beaded liner. It supposedly can be hooked onto the wall directly using the integrated jhook or have the j-hook section removed and used a beaded liner. All of the liners I have discussed so far have a wall height associated with them and a seam us used to create the walls of the liner with a flat bottom.
An overlap liner does not have a wall height. To my knowledge, they are a large, flat piece of liner material that is overlapped the top seat of the pool until it barely touches the ground inside the pool and the liner is filled with water. the liner is stretched over the top seat at the top of the wall as the water fills the liner, the liner is slowly let back into the pool untill the water fills the entire bottom surface and partially up the walls. When the water starts up the wall, the top seat is removed in sections and the liner is pulled down the sidewall wit the extra liner material being cut off and the raw edge is tucked under the folded overlapping liner. A coping srip is then added and the top seat goes back on. This process is repeated until the entire liner is "stretched into" the pool.
Back to my experience. I had the beaded liner in hand but could not use it because I didn't have receivers. I went to the LPS and she said they have never sold receivers as they didn't like that a bead liner could pull from the receiver and there were several different bead profiles and you needed to make sure you had the correct one. They only sold j-hooks like mine and overlaps as that is what Doughboy uses and they are the best if you have a deep end pool (overlaps can be stretched into the deep end) . Back o the Internet... I learned I needed 17 receivers for my pool and that they were $5 - $13 each and the only person to stock them near me wanted 13 each.. $200 for me..to hang my $200 liner, assuming they were the correct profile.
In the end, I bought a 21 foot round, 52 inch tall j-hook liner for $190, delivered and I returned the beaded liner with a15% restocking fee plus shipping. I installed it myself in a few hours.
